No. Residue, mineral deposits and changes to the finish can look similar. Appearance alone cannot establish which is present.
What the observation means
Consider what contacted the surface and when the marks appeared. A wet cooking method, spill or unsuitable chemical gives different context from normal dry use. Repeated abrasive scrubbing can turn a cosmetic issue into surface damage.
A useful next step
Check the care instructions and retain the product details if a cleaner was used. Stop increasing chemical strength when approved cleaning does not remove the mark. Report flaking, cracking or sharp exposed edges separately from a smooth discolouration, and avoid treating a finish problem as proof of a heater fault.
Manuals and supporting guidance
Model-specific instructions take priority. These references support the practical principles discussed here; they do not diagnose your appliance.